Question

If the roots of the quadratic equation x2 + 4x + k = 0 are equal then the
value of k is-

(a) –4 (b) (1/4)
(c) -2/3
(d) 1​

Answer 1

Answer:

$\red { Value \: of \: k } \green {= 4 }$

Step-by-step explanation:

Compare x² + 4x + k = 0 with ax² + bx + c = 0 , we get

a = 1 , b = 4 , c = k

Discreminant (D) = 0 [ Roots are equal ]

=> b² - 4ac = 0

=> 4² - 4 × 1 × k = 0

=> 16 - 4k = 0

=> -4k = -16

/* Divide each term by (-4), we get

=> k = 4

Therefore.,

$\red { Value \: of \: k } \green {= 4 }$

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Answer 2

Answer :

Kindly recheck the options. It may also happen that the Options are wrong.

But the correct answer is ---> k = 4

Step-by-step explanation:

p(x) = x² +4x + k

Since, The roots of the quadratic equation are equal.

therefore, discriminant (D) = b² -4ac = 0

In the given quadratic equation,

Here, a = 1 , b = 4 and c = k

Then, b² - 4ac = 0

=> (4)² - 4 (1 )(k) = 0

=> 16 - 4k = 0

=> -4k = -16

=> k = -16/-4

=> k = 4

Answer

I Hope This Helped You...